In the field of display technologies, display panels can be divided into three types: out-cell, on-cell and in-cell, depending on a difference in the position of a touch sensor. For an out-cell type display panel, the touch sensor is directly formed on the display panel, which increases an overall cell thickness and reduces the light transmittance. For an on-cell type display panel, the touch sensor is formed on an outer side of a counter substrate of the display panel, which decreases the overall cell thickness, but increases a process for fabricating a counter substrate. In contrast, in an in-cell type display panel, the touch sensor is directly formed inside the display panel, which not only avoids increase of the overall cell thickness, but also simplifies the manufacture process by fabricating the touch sensor together with the display panel. By virtue of advantages mentioned above, in-cell technology is becoming more and more popular in the field of display and has gradually become the mainstream technology.
For some in-cell type display panels, when a sensing electrode of the touch sensor is located on an array substrate of the display panel and a corresponding touch electrode is also located on the array substrate or on a counter substrate of the display panel, it is usually necessary to form conductive gold balls between the array substrate and the counter substrate so as to enable transmission of a touch signal between the array substrate and the counter substrate. However, in this solution, the conductive gold balls can easily cause non-uniformity of the overall cell thickness, which then gives rise to display defects such as light leakage. Likewise, for an ordinary display panel, i.e., an out-cell type or on-cell type display panel, various electric signals and power supplies are generally provided at the array substrate, so generally it is also necessary to realize conduction between the array substrate and the counter substrate.